OBJECTS OF THE INVESTIGATIONS 147 



about Blue and Fin Whales suggests that these species have habits similar to those of 

 the Humpback. 



In the economic study of whales it is of the utmost importance that we should have 

 fuller and more accurate knowledge of these migrations. From what has been stated 

 above it will be seen that north and south migrations of the three most valuable species 

 may be inferred, but we have as yet next to no knowledge of the routes taken and not 

 a particle of evidence regarding east and west movements. 



To ascertain whether such east and west movements exist is most essential ; for if 

 the whales move freely round the Antarctic Continent it follows that the southern stock 

 forms a single entity: excessive hunting in any one area will affect all areas adversely. 

 If, on the other hand, such movement does not exist, the depletion of one area will not 

 reduce the stocks in other parts. 



In tracing the migrations of fish the method most generally adopted is that of marking. 

 Fish are caught, suitable marks bearing a reference number are attached to them, and 

 they are then liberated. A proportion of these marked fish are recaptured in the course 

 of commercial operations, and the offer of a reward increases the chance that the mark, 

 together with the necessary data, will be returned to the fishery authority. By this 

 means valuable information on the migrations of fish has been obtained, and some 

 years ago it was suggested that a similar method might usefully be employed with 

 whales. It is, for obvious reasons, more difficult to mark whales than fish, but as a 

 result of experiments made before the 'Discovery' sailed on her first commission, a 

 practicable method was discovered. The method is explained on p. 208. 



In considering the design of a second ship for investigations in the south, the Com- 

 mittee attached great importance to this question of whale-marking. A vessel of com- 

 paratively high speed was necessary, built generally on the lines of a whale-catcher, 

 but it was recognized that she would also be required to assist in routine work on 

 plankton and hydrology, and it was also considered desirable that she should carry a 

 full-sized otter trawl for the exploration of certain areas in the Dependencies which 

 might prove commercially profitable. 



These varied requirements have been successfully met in the Research Steamship 

 'William Scoresby'. This vessel is named after the celebrated whaling captain, whose 

 Account of the Arctic Regions, published in 1820, may be regarded as the first scientific 

 contribution to the study of whaling. The ' William Scoresby ' was launched at Beverley 

 on December 31, 1925, and except for a brief return visit to England in 1927 has since 

 been almost continuously at work in the south. 



It will be seen, from what has been said above, that in the organization of research 

 into whaling problems the Discovery Committee is proceeding on three separate lines 

 of enquiry. The work at the Marine Biological Station is designed to supply essential 

 information on the biology of whales themselves, while the vessels are engaged in a 

 study of the environment of whales and in experiments from which a knowledge of 

 their migrations may be derived. 



Reference has already been made to the work on whales carried out at Saldanha Bay 



